Wire wrapping apparatus with terminal detector

ABSTRACT

An apparatus for wrapping wire on a terminal is provided with a sensing rod extending through the center of the wire attaching tool to detect the proper working relationship of the tool with respect to the terminal. The tool includes an elongated bit element and an inner wrapping sleeve, which rotate to wrap the wire, and an outer stationary sleeve to protect adjacent wrapped terminals. A pneumatic cylinder shifts the sleeves to load the stripped wire in a groove in the bit element and longitudinally extending slots are provided in the sleeves for allowing the stripped end to move into the groove. A motor is provided for rotating the tool to effect the wrapping on the terminal. On the sensing rod, a first end extends into a central bore of the bit element that receives the terminal, and the opposite or second end of the rod responsively operates a spring biased piston, in turn tripping a stationary mounted photo-cell switch. The photocell activates an interlock means in the control circuit to enable the proper operation of the motor, i.e., only when the terminal is properly inserted in the bore.

United States Patent Fidiam Apr. 29, 1975 WIRE WRAPPING APPARATUS WITHTERMINAL DETECTOR John F. Fidiam, 13133 Madonna Ln., Fairfax, Va. 22030Filed: Sept. 27, 1973 Appl. No.: 401,390

[76] Inventor:

References Cited UNITED STATES PATENTS 12/1956 Greer 29/203 DT 3/1964Self 29/203 DT Prinmry Examiner-Thomas H. Eager Attorney, Agent, orFirmMillen, Raptes & White [57] ABSTRACT An apparatus for wrapping wireon a terminal is provided with a sensing rod extending through thecenter of the wire attaching tool to detect the proper workingrelationship of the tool with respect to the terminal. The tool includesan elongated bit element and an inner wrapping sleeve, which rotate towrap the wire, and an outer stationary sleeve to protect adjacentwrapped terminals. A pneumatic cylinder shifts the sleeves to load thestripped wire in a groove in the bit element and longitudinallyextending slots are provided in the sleeves for allowing the strippedend to move into the groove. A motor is provided for rotating the toolto effect the wrapping on the terminal. On the sensing rod, a first endextends into a central bore of the bit element that receives theterminal, and the opposite or second end of the rod responsivelyoperates a spring biased piston, in turn tripping a stationary mountedphoto-cell switch. The photo-cell activates an interlock means in thecontrol circuit to enable the proper operation of the motor, i.e., onlywhen the terminal is properly inserted in the bore.

13 Claims, 4 Drawing Figures ADVANCE MOTOR AND REI'RAC'I' OONTROLSOLENOlD CIRCUIT VALVE INTERUXX MEANS PRESSURE SOURCE WIRE WRAPPINGAPPARATUS WITH TERMINAL DETECTOR FIELD OF THE INVENTION The presentinvention relates to apparatus for attaching conductors to terminalboards, and more particularly, to apparatus for assuring proper wirewrapping of stripped ends of wires on electrical terminals,

BACKGROUND OF THE INVENTION The making of solderless wrapped connectionson electrical terminals is a standard in the electronics industry forinterconnecting all types of electrical circuitry, such as in computerand in communication circuits. There have been provided in the past manyways proposed for making the wrapped connections. These may be generallyclassified as: (1) manual, utilizing a rotary driving tool; (2)semi-automatic, utilizing the same type of hand tool, but with automaticposition pointers for the operator; and (3) automatic, utilizingmechanical means for both the location identification and the toolactivation. In all three types of operations. but particularly in thethird category mentioned, there has existed a problem of improperactivation of the rotating tool; i.e., rotating the tool prior to thebit being properly positioned on the terminal to be wrapped. If the toolis activated prior to the terminal being inserted into the axiallyextending bore in the end of the bit element. the wire rotatesuncontrollably and either becomes tangled in a helical coil, if the toolis not on a terminal at all, or the wire wrap may be made at an improperZ-level if the tool is on the terminal, but just not seated properly. Ineither situation, the wrapping operation must be interrupted, the wirereplaced, and the tool reloaded before the procedure can bereinstituted, with consequent loss of valuable production time.Particularly in automatic machines, the computer controlled sequencingis also interrupted, and the possibility exists that when the machine isrestarted improper connection of terminals is caused and thus a completeinoperative terminal board may be wired and must be destroyed.

Perhaps the greatest single cause of the tool not properly picking upthe terminals as it moves in to perform a wire wrapping operation isbent terminals, i.e., a terminal that has been slightly bent from thenormal or perpendicular relationship with respect to the board beingwired. There are also occasions when improper or inadequate zeroing" ofthe machine occurs, or simply when human error enters the picture in themanual type operation and the motor is prematurely activated on the handtool.

OBJECTIVES OF THE INVENTION Thus, it is a main object of the presentinvention to provide a wire attaching apparatus wherein a precedentrequirement to activation of the tool is detection of the proper workingrelationship of the tool with respect to a reference, such as theterminal to which the wire is to be attached.

It is still another object of the present invention to provide a sensingmeans associated with the tool such that the tool may be reliablyoperated, either in a hand or automatic mode, only when the terminalreceiving bore of the tool is properly engaged on the terminal.

It is still another object of the present invention to provide animproved wire wrapping apparatus with a simple sensing means includingan axially extending sensor rod housed within the bit element of a wirewrapping tool.

BRIEF DESCRIPTION OF THE INVENTION In accordance with the presentinvention, a wire attaching apparatus is provided with a simple,fool-proof sensing means for determining the proper relationship betweenthe tool and the terminal to which the wire is being attached before themeans for activating the tool may be operated. More specifically, thepresent invention relates to a wire wrapping apparatus with terminalsensor means that is incorporated directly into a wire wrapping tool andserves to mechanically detect the proper working relationship betweenthe tool and the terminal. To assure that the main control circuitactually performs the initiation of the wrapping operation so that thesequencing integrity and proper Z-level location is maintained, aninterlock means is imposed as an interface between the sensing means andsaid control circuit.

The rotary wrapping tool disclosed includes an elongated bit element, aninner wrapping sleeve, and an outer protector sleeve. The usual terminalreceiving bore is formed in the face of the bit element, and inaccordance with the invention, the sensing means advantageously includesan axially shiftable rod housed along the center axis of the bitelement. The first end of the rod extends into the receiving bore tosense the end of the terminal and switch means is actuated by axialmovement of the rod upon engagement.

The sensor rod, in accordance with more specific features of the presentinvention, extends through the bit to a second end to engage a linkagemeans in the form of an axially shiftable piston and spring means. Anactuator cylinder for the switch means is carried by the piston rod ofsaid piston. The switch means comprises a photo-cell that is connectedto the interlock means in the control circuit, which in turn allowsoperation of a solenoid valve for providing air pressure to rotate thetool driving motor.

The second end of the sensor rod includes another important feature inthe form ofa reverse offset extension member in a guide block. Thiselement prevents relative rotation between the rod and the guide blockfor assuring accurate operation, to prevent interference with the wireduring loading, and to limit the axial movement of the rod under thespring bias of the spring associated with the linkage piston. Theactuator cylinder carried on the rod of the piston is sufficiently longto assure tripping of the photo-cell on at least two Z- levels of wireattachment to the terminal. The wrapping tool may include the groove forhousing the stripped wire in the bit element with a slot in each of thesleeves to permit loading of the wire by movement into said groove.

Still other objects and advantages of the present invention will becomereadily apparent to those skilled in this art from the followingdetailed description, wherein I have shown and described only thepreferred embodiment of the invention, simply by way of illustration ofthe best mode contemplated by me of carrying out my invention. As willbe realized, the invention is capable of other and differentembodiments, and its several details are capable of modification invarious obvious respects, all without departing from the invention.Accordingly, the drawings and description are to be regarded asillustrative in nature, and not as restrictive.

DESCRIPTION OF THE DRAWING FIG. 1 is a partial side view of a wirewrapping apparatus, partially in cross-section, showing the preferredembodiment for carrying out the principles of the present invention;

FIG. 2 is an enlarged cross-sectional view of the wrapping tool andshowing the relationship of the tool on the terminal in readiness forthe wrapping operation;

FIG. 3 is a cross-sectional view taken along line 33 of FIG. 2 with thestripped wire lying in position in the groove for wrapping; and

FIG. 4 is a partial cross-sectional view taken along line 44 showing thepreferred photo-cell switching means.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT With reference now toFIG. 1 of the drawings for a more detailed look at the preferredembodiment shown for illustrating the principles of the presentinvention, there is provided a wire wrapping apparatus or head.generally designated by the reference numeral 500. The wire wrappinghead includes a main frame 511 shown in part in this figure. Within themain frame is provided a wire catching and loading means, partiallyshown and generally designated by the reference numeral 512. Anadvancing and retracting means for the head 500 is shown schematicallyat 514. The wire wrapping head also normally includes a stripping andcutting means for the wire. however, this is not shown in the presentdrawings since a showing is not required for a general understanding ofthe present invention. It should be understood that the broad inventiveconcepts disclosed herein, while applicable to incorporation in theautomatically operable embodiment shown, said concepts are equallyuseful in hand tools for manual and semi-automatic operations, mentionedabove.

Thus. with this in mind and proceeding to describe FIG. I, there isshown a suitable terminal board B with a terminal or pin t extendingnormally outward from the face of said board. It is to be assumed that awire W is to be wrapped on the terminal t so as to make an acceptableelectrical connection, as discussed in my previous application. The wireW is shown as already stripped and loaded in a rotary wire wrapping tool515, which is preferably of the side loading type. The tool 515 is ofthe concentric type, that is, it is to receive the terminal I along thecentral longitudinal axis and is to rotate about said central axis. Thispermits wrapping the wire W without up and down vibration of the tooland does away with any requirement for special means for accommodatingsuch movement and generally gives superior results, also as furtherdiscussed in my previous application.

As perhaps best illustrated in the enlarged view of FIG. 2, said tool515 includes a stationary outer sleeve 520, an inner sleeve 521, a bitelement 522, and finally a sensor rod 523; all parts being concentric,as shown. The stationary sleeve 520 is adapted to be held againstrotation by a bracket 524 mounted on an axially moveable carriage 525,which serves to load the wire end,

also as illustrated (FIGS. 1 and 2). The inner sleeve 521, the bitelement 522, and the sensor rod 523 are adapted to be driven in unisonby motor 526 carried on the carriage 525. The gears 527 and 528, andsuitable keying means (not shown) between the gear 528 and the sleeve521, complete the rotary driving mechanism.

As is evident to those skilled in the art, after the wire W has beenloaded in the tool 515 by the forward shifting action of the carriage525 by pneumatic cylinder 530, the advancing and retracting means 514 isacti' vated to relatively move the entire head 500 with respect to theterminal I. This action brings the tool 515 first to the intermediateposition shown in FIG. 1, and finally to the operational position, shownin FIG. 2. In the intermediate position, the forward face of the tool 515 just touches the tip of the terminal 1. Assuming that the terminal Iis not bent, and that the .r-y locator (not shown) for the head 500 hasproperly performed its operation, the terminal I is thus positionedproperly for receipt into bore 531 of bit element 522 (see FIG. 1). Inthe final operational position (see FIG. 2) the proper relative positionfor wrapping the wire W is reached; that is, the position with theterminal I fully enclosed in said bore 531. It will be understood thatthe showing of FIG. 2 assumes the wrapping operation is to take place atthe first Z-level, that is adjacent the face of the board B. As will befurther understood, when wrapping at other Z-levels (such as the secondand third Z-levels) is required, the head 500 is simply stopped betweenthe initial contact position of FIG. 1 and the first Z-Ievel position ofFIG. 2 by some outside operating means (not shown).

The sensor rod 523 operates switch means (to be fully described below)and thus serves the important function of assuring that the terminal Iis properly received (at the desired Z-level) in the bore 531. Thesensor rod 523 forms with other elements to be described below, a uniqueand highly simplified sensing means that is not only low in cost ofmanufacture, but highly sensitive and reliable in operation. If theterminal t is not within the bore 531, no longer will the tool beallowed to proceed to rotate causing tangled wires where a terminal Ihas not been engaged, or an improper wrap where the terminal has notbeen fully engaged. Down time of wrapping stations or machines due tothis problem is eliminated thereby greatly enhancing the productioncapabilities of any installation.

Proceeding with describing of more details of the inventive apparatus,the first end of the sensor rod 523 is located at the working end of thetool 515 and is axially slideable in bore 544 extending rearwardly ofthe terminal receiving bore 531 and mating exactly therewith. Radiallyspaced from the bore 544, 531 is a parallel groove 545, which holds thestripped end of the wire W in position ready to be wrapped on theterminal I when the tool is rotated by the motor 526. Notch 546 on thebit element is for positioning the wire W just before loading, and it isto be understood that if necessary, the rod 523 may be correspondinglynotched. Such a notch 546a in the rod extends sufficiently along thelength so as to be always contiguous with the notch 546 regardless ofthe axial position of said rod 523. In other words, the notch 546a inthe rod is at least the length of the notch 546, plus the length oftravel of the rod 523 during the sensing operation. This feature doesallow the radial dimension of the tool to be kept to a minimum tofacilitate operation on a circuit board with closely spaced terminals.The tip of the stripped end of the wire W may lie in the notch 546 asthe tool is moved on the terminal without fear of interference by therod 523 with this construction.

Slots 547, 548 on the outer and inner sleeves 520, 521 respectively. arealigned at the bottom of the tool by the indexing means (not shownherein. but described in my prior application) to allow the wire to movethrough the notch 546 and into the groove 545. The slot 548 moves fromalignment with the slot 547 as the rotation for wrapping occurs but isof course realigned when the next indexing operation occurs on the nextwrapping cycle. The stationary sleeve 520 prevents the edges of the slot548 from hitting and cutting insulation of wires on adjacently wrappedterminals during rotation of the tool 515 thereby obviating a seriousproblem of the past. The stationary sleeve 520 thus serves as protectionfor the adjacent wires. In addition, the sleeve 520 serves as astabilizing guide for the rotating parts of the tool. and as aprotective casing for the parts.

With the first end of the axially shiftable sensor rod 523 located andfunctionally associated with the adjacent parts of the tool 515 and theoperation of the tool itself fully explained above, reference can now bemade to the opposite end of said tool. shown at the left hand side ofFIG. 1. Thus. the second or opposite end of the rod 523 emerges from thebore 544 at the end of the bit element 522. Encompassing said second endof the sensor rod 523 is a guide block 550 fixed against relativerotation and axial movement with respect to the bit element 522 by asuitable set screw 55]. A reverse offset extension member 552 isprovided at the very end of the sensor rod 523 and this member isengaged in an offset bore (not numbered) in the face of the block 550.This arrangement prevents relative rotational movement of the rod withrespect to said guide block 550 and. in turn, with respect to the bitelement 522. This function is particularly important in the instancewhere the rod 523 must be notched along its length in order to mate withthe loading notch 546 (see FIG. 2).

The linkage means between the switch to be controlled and the describedsecond end of the sensor rod 523 takes the form of a slideable piston555 with piston rod 556 housed and guided in guide cap 557, mounted on ashoulder of the guide block 550 and fixed by set screw 558. A spring 559is positioned inside the cap 557 so as to urge the piston 555, and inturn the rod 523, forwardly or toward the first end. In operation, itwill be understood that when the terminal t is properly engaged and thesensor rod 523 has been shifted axially rearwardly, the spring 559 iscompressed. Pressure is thus constantly exerted to move the rod 523 backto the original position (FIG. 1) so that when the tool has been backedoff the terminal I (subsequent to the wrapping operation). the switchmeans is automatically deactivated. No further resetting is required forthe next tool sensing operation and subsequent wrapping operations mayproceed.

To actually perform the switching operation, an actuator cylinder 560 ispositioned on the tip of the piston rod 556, which cylinder is adaptedto move freely in a passage 561 formed in a stationary housing block562. As best shown in FIG. 4, the switch means that is operated by thecylinder 560 is a photo-cell switch 563. The photo-cell is positioned tolook across the passage 561 where interception of a light beam fromlight source 565 occurs when the cylinder 560 is shifted to the dottedline position (shown in FIG. 1). This represents movement of the tool515 by the advancing and retracting means 514 full on the terminal 1(shown in FIG. 2); the photo-cell 563 thereby being tripped and anelectrical signal being transferred over leads 564 to control circuit570. It should be noted that the actuator cylinder 560 initially tripsthe photo-cell 563 prior to being positioned at the dotted line positionof FIG. 1, and as will be realized, this feature permits the sensingmeans to also operate when the second and/or third Z- levels are to bewrapped. The only change in the mode of operation is that the light beamis intercepted in the final position by the middle and opposite end ofthe cylinder 560, respectively.

Preferably, the control circuit 570 through interconnecting means thatincludes an interlock means 571 and the leads 564 are connected to thephoto-cell switch 563. This assures that the exact point of interruptionof the light beam is not critical since the control circuit 570, not thephoto-cell switch 5633, actually initiates the actuation of solenoid 572by the proper builtin sequencing and timing. The interlock means 571serves to disable the control circuit 570 from operating said solenoid572 when the terminal I is not properly positioned in the bore 531. Thesolenoid 572 is operable to control the supply of pressurized air frompressure source 573 through transfer conduit 574 to the motor 526.

Briefly summarizing the operation. when a terminal I is detected by thesensor rod 523., the cylinder 560 blocks the light path and trips thephoto-cell switch 563. The interlock means 571 enables the controlcircuit 570, and in turn, the solenoid 572 is properly actuated insequence by said control circuit to open the valve for air pressure todrive the motor 526 and thereby rotate the tool 515. The importantfactor is that only under the condition of the photo-cell 563 beingtripped can the motor 526 be actuated in accordance with the presentinvention, and therefore false or improper wrapping operations areavoided.

It is to be understood that the apparatus of the preferred embodimentdescribed hereinabove may be modified or changed in certain respectswithout departing from the basic broad principles of the presentinvention. For example, different wrapping tools with differentstructural parts and/or operating surfaces and different types ofsensing means and switch means may be used if desired. Accordingly, itis to be understood that the invention is capable of use in such variousother combinations and environments and is capable of changes ormodifications within the scope of the inventive concept as expressed inthe following claims.

What is claimed is:

1. In a wire attaching apparatus for connecting a wire end to a terminalincluding a wire attaching tool adapted to relatively move with respectto said terminal into working relationship. and means to activate saidtool to provide the connection, the improvement comprising sensing meansassociated with said tool to detect the proper working relationship ofsaid tool with respect to said terminal and means interconnecting saidsensing means to said activating means to assure operation only whensaid tool is properly positioned.

2. In the wire attaching apparatus of claim 1 wherein saidinterconnecting means includes interlock means responsive to saidsensing means for enabling operation of said activating means only whenthe proper relationship between said tool and said terminal is provided.

3. In the wire attaching apparatus of claim 1 wherein said tool is arotary wrapping tool including an elongated bit element and wrappingsleeve, and said sensing means includes an axially shiftable rod housedin said bit element, a bore in one end of said bit element to receivesaid terminal, a first end of said rod extending into said bore, andswitch means actuated by axial movement of said rod upon engagement ofsaid first end with said terminal.

4. The apparatus of claim 3 wherein said rod includes a second endextending from the end of said bit element opposite said one end, saidswitch means being operative in response to movement of said second end.

5. The apparatus of claim 4 wherein is further included linkage meansbetween said second end and said switch means, spring means to bias saidlinkage means and said rod in the direction of said first end.

6. The apparatus of claim 5 wherein is further included a reverse offsetextension member on said rod adjacent said second end, a guide blockmounted on said bit element. and an offset bore in said block receivingsaid extension member to prevent relative rotational movement of saidrod with respect to said guide block and to limit axial movement of saidrod toward said first end.

7. The apparatus of claim 5 wherein said linkage means includes a pistonmember abutting said second end, a guide cap slideably enclosing saidpiston attached to said guide block and an actuator cylinder on thepiston to operate said switch means.

8. The apparatus of claim 7 wherein said switch means includes aphoto-cell, means for generating a light beam directed toward saidphoto-cell. said actuator cylinder serving to break said light beam.

9. The apparatus of claim 8 wherein said actuator cylinder issufficiently long to assure tripping of said photo-cell on at least twolevels of wire attachment to said terminal.

10. A wire wrapping apparatus for connecting a wire with a stripped endto a terminal comprising a rotary wire wrapping tool, including anelongated bit element and inner wrapping sleeve on the same, a bore inthe end of said bit element for receiving the terminal, means torelatively move said tool and said terminal into working relationshipwith said terminal inserted in said bore, a stationary outer sleeve, alongitudinally extending groove in said tool and slot in at least saidinner sleeve for receiving the stripped end, motor means for rotating atleast said inner sleeve to wrap the wire on said terminal, control meansfor activating said motor means, and sensing means associated with saidtool to detect the proper insertion of said terminal in said bore and toresponsively operate said control means, whereby operation of said motormeans and rotation of said inner sleeve is permitted only when wrappingon said terminal may take place.

11. The apparatus of claim 10 wherein said control means includesinterlock means responsive to said sensing means for enabling operationof said motor means only when said terminal is properly inserted in saidbore.

12. The apparatus of claim 10 wherein said sensing means includes anaxially shiftable rod in said bit element, said bit element including aside loading notch and corresponding elongated notch means in said rod.

13. The apparatus of claim 12 wherein said notch means is sufficientlylong to obviate interference with said wire during the loading andwrapping operations. =l =l

1. In a wire attaching apparatus for connecting a wire end to a terminalincluding a wire attaching tool adapted to relatively move with respectto said terminal into working relationship, and means to activate saidtool to provide the connection, the improvement comprising sensing meansassociated with said tool to detect the proper working relationship ofsaid tool with respect to said terminal and means interconnecting saidsensing means to said activating means to assure operation only whensaid tool is properly positioned.
 2. In the wire attaching apparatus ofclaim 1 wherein said interconnecting means includes interlock meansresponsive to said sensing means for enabling operation of saidactivating means only when the proper relationship between said tool andsaid terminal is provided.
 3. In the wire attaching apparatus of claim 1wherein said tool is a rotary wrapping tool including an elongated bitelement and wrapping sleeve, and said sensing means includes an axiallyshiftable rod housed in said bit element, a bore in one end of said bitelement to receive said terminal, a first end of said rod extending intosaid bore, and switch means actuated by axial movement of said rod uponengagement of said first end with said terminal.
 4. The apparatus ofclaim 3 wherein said rod includes a second end extending from the end ofsaid bit element opposite said one end, said switch means beingoperative in response to movement of said second end.
 5. The apparatusof claim 4 wherein is further included linkage means between said secondend and said switch means, spring means to bias said linkage means andsaid rod in the direction of said first end.
 6. The apparatus of claim 5wherein is further included a reverse offset extension member on saidrod adjacent said second end, a guide block mounted on said bit element,and an offset bore in said block receiving said extension member toprevent relative rotational movement of said rod with respect to saidguide block and to limit axial movement of said rod toward said firstend.
 7. The apparatus of claim 5 wherein said linkage means includes apiston member abutting said second end, a guide cap slideably enclosingsaid piston attached to said guide block and an actuator cylinder on thepiston to operate said switch means.
 8. The apparatus of claim 7 whereinsaid switch means includes a photo-cell, means for generating a lightbeam directed toward said photo-cell, said actuator cylinder serving tobreak said light beam.
 9. The apparatus of claim 8 wherein said actuatorcylinder is sufficiently long to assure tripping of said photo-cell onat least two levels of wire attachment to said terminal.
 10. A wirewrapping apparatus for connecting a wire with a stripped end to aterminal comprising a rotary wire wrapping tool, including an elongatedbit element and inner wrapping sleeve on the same, a bore in the end ofsaid bit element for receiving the terminal, means to relatively movesaid tool and said terminal into working relationship with said terminalinserted in said bore, a stationary outer sleeve, a longitudinallyextending groove in said tool and slot in at least said inner sleeve forreceiving the stripped end, motor means for rotating at least said innersleeve to wrap the wire on said terminal, control means for activatingsaid motor means, and sensing means associated with said tool to detectthe proper insertion of said terminal in said bore and to responsivelyoperate said control means, whereby operation of said motor means androtation of said inner sleeve is permitted only when wrapping on saidterminal may take place.
 11. The apparatus of claim 10 wherein saidcontrol means includes interlock means responsive to said sensing meansfor enabling operation of said motor means only when said terminal isproperly inserted in said bore.
 12. The apparatus of claim 10 whereinsaid sensing means includes an axially shiftable rod in said bitelement, said bit element including a side loading notch andcorresponding elongated notch means in said rod.
 13. The apparatus ofclaim 12 wherein said notch means is sufficiently long to obviateinterference with said wire during the loading and wrapping operations.